package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.FOLLOW_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {
    @Autowired
    private IUserService userService;
    private final StringRedisTemplate stringRedisTemplate;

    public FollowServiceImpl(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    @Override
    public Result follow(Long id, Boolean isFollow) {
        UserDTO user = UserHolder.getUser();
        if (!isFollow){
            //删除数据
            boolean isRemove = remove(new QueryWrapper<Follow>().eq("user_id", user.getId()).eq("follow_user_id", id));
            if (isRemove){
                //删除redis中的记录
                stringRedisTemplate.opsForSet().remove(FOLLOW_KEY +user.getId().toString(), id.toString());
            }

        }else {
            //往follow表里面插入数据
            Follow follow =Follow.builder()
                    .userId(user.getId())
                    .followUserId(id)
                    .build();
            boolean isSave = save(follow);
            if (isSave){
                //结果插入到redis中
                stringRedisTemplate.opsForSet().add(FOLLOW_KEY +user.getId().toString(),id.toString());
            }

        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long id) {
        UserDTO user = UserHolder.getUser();
        Integer count = query().eq("user_id", user.getId()).eq("follow_user_id", id).count();

        return Result.ok(count>0);
    }

    @Override
    public Result commonFollow(Long id) {
        //基于redis的set获取共同关注
        UserDTO user = UserHolder.getUser();
        Set<String> commonFollow = stringRedisTemplate.opsForSet().intersect(FOLLOW_KEY + user.getId().toString(), FOLLOW_KEY + id.toString());
        if (commonFollow==null||commonFollow.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        //类型转换
        List<Long> userIds = commonFollow.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> userDTOS = userService.listByIds(userIds).stream()
                .map(item -> BeanUtil.copyProperties(item, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(userDTOS);
    }
}
